Monday, May 14, 2007

Moon dust 4, Inventors 0

Memo to NASA: Next time you want to deliver a package to the Moon, don't call UPS.

That was one of the lessons learned this weekend at the Regolith Excavation Challenge, a competition in which four teams of backyard inventors vied to dig as much simulated lunar soil as possible in half an hour.

As it turned out, none of the teams excavated the minimum 150 kilograms of simulant needed to win the $125,000 first prize.

Geoffrey Pulk of Berkley, Michigan, got some praise for his design – a buzzsaw-like rotor of steel buckets that used, among other things, a wood frame, a bike chain and a conveyor belt made from his girlfriend's old jeans.

But unfortunately, he made a fatal mistake: He sent his machine to Santa Maria, California, where the contest was held, via the aforementioned package delivery service. Though it had been securely boxed in a wooden crate, the crate was broken and the nearly indestructible steel buckets were mangled.

"You'd have to jump on it to do that much damage," he said. Within 10 minutes of operation, a solder joint of one of the buckets broke, and the broken piece snagged the conveyor belt and brought his machine to a halt. "I'm upset. It was built properly, but damaged in shipment," Pulk said. "I could have handled a design flaw, but it worked like we designed it to, to a tee."

Jess Leyva of The Aerospace Corporation, a judge, said he could "feel Pulk's pain". He pointed out that NASA has suffered similar setbacks: for example, the high-gain antenna of the Galileo probe to Jupiter was damaged beyond repair when it was en route to Florida.

By the day's end, Pulk was smiling again. In a second unofficial run, his repaired machine scooped up 2.8 kg per minute. That was still short of the 5-kg target, but enough to prove that his concept worked. He vowed to come back next year with three design ideas, including, he says, one "so obvious that it made me slap my forehead and say, 'Why didn't I think of that earlier?'"

Of the remaining teams, Technology Ranch of Pismo Beach, California, was the only one to run 30 minutes on its first attempt, scooping 75 kg (although 10 kg missed the collection box into which the simulant was meant to be dumped).

Designer Jim Greenhaw, who mentors a high-school robotics team, drew praise for his compact and neat design; his machine kicked up much less dust than his rivals.

A student team from the University of Missouri at Rolla, led by Masafumi Iai, failed spectacularly when its motor overheated as it tried to dig through the unexpectedly thick, clumpy regolith (a close-up of one of the cogs in the team's entry is shown at left). "eBay, here we come!" said team member Joel Logue as the smoke rose from the burned-out motor.

Todd Mendenhall, a former champion of Robot Wars US and an engineer at "a major aerospace defense corporation", acknowledged from the beginning that his machine, called the Big Friggin' Digger, was not ready to win the prize yet.

The machine's lawnmower-like roller and cutter gathered much more regolith than expected, but the excess gunked up the conveyor belts and caused the machine to grind slowly to a halt. "The cutter is cool, but the transportation method is too complicated," said judge Rob Mueller of NASA's Kennedy Space Center.

That doesn't mean the design was a failure, Mueller said. "We [NASA] are here to collect ideas, not necessarily complete systems."